1. Field of the Invention
This invention is directed to a method and apparatus for aiding an operator in executing step by step procedures during the operation of a complex process facility such as a nuclear power plant. More particularly, it involves a computer based system which incorporates monitored plant data and interactive plant operator responses to recommended actions for step by step progression through a selected procedure while simultaneously providing parallel information which allows the operator to assess other plant conditions which may require attention.
2. Prior Art
The operation of a complex process facility requires the assimilation of a large amount of data, an evaluation of the status of the process and the various component systems from those data, and informed, decisive action based upon such evaluation. While much of the operation of the modern complex process facility is automatically controlled, overall supervision of the facility is always the responsibility of a human operator. Even in a highly automated facility, there are usually normal operating and maintenance, and in some instances, surveillance procedures, which require action by a human operator. Abnormal and emergency operating conditions invariably call for further intervention by the operator.
Typically, the operator of the complex process facility is provided with written or "paper" procedures whereby the steps to be followed are presented in the form of verbal statements on a printed page. These paper procedures require the human who is responsible for carrying out the actions and operations described in the appropriate procedure to read the procedure text, gather specified data and filter the data through preset evaluation logic to identify recommended action steps. The paper procedures often require the human operator to simultaneously monitor other conditions affecting the status of the facility while following the current step by step procedure. In effect, this requires the operator to remember the requirement to monitor the status condition and to periodically check for data related to that condition.
One type of facility in which paper procedures are used to guide the human operator in effective management of a complex process is a nuclear power plant. Extensive paper procedures are used in these facilities, especially during emergency conditions following a reactor trip. Subsequent to the accident at Three Mile Island Unit 2 in 1979, the U.S. Nuclear Regulatory Commission issued requirements which have led to a dramatic increase in both the breadth and depth of Emergency Operating Procedures (EOP) at nuclear power plants. In response to these expanded requirements, the Westinghouse Owners Group has developed written generic guidelines which have subsequently been adapted to meet the specific needs and characteristics of the various nuclear generating units represented by the Owners Group and have been issued to the generating crews of the units as Emergency Operating Procedures. These procedures contain explicit directions for the control room operations crew to implement appropriate emergency response strategies. However, the individual charged with implementing such strategies (typically a Senior Reactor Operator [SRO]) remains tied to static procedures, considering changes to plant status in serial fashion, and is potentially unable to properly develop an overview of the plant condition.
Commonly owned U.S. Pat. No. 4,552,718 describes a system which generates meaningful information for the operator of a pressurized water reactor (PWR) on six critical safety functions which must be maintained or reestablished, if lost, during emergency operation. The system uses a status tree approach to generate automatically, or through manual responses by an operator, a visual indication of the current status of all six critical safety functions. The display is color coded from green, through yellow and orange, to red to indicate the degree of threat to each safety function. This system is used in conjunction with the paper procedures to alert the operator, who is absorbed in the steps of a particular emergency procedure, to the overall condition of the plant as expressed by the status of the six critical safety functions. The visual presentation also includes the title of the paper procedure to which the operator should turn to find the sequence of steps to be followed in mitigating the effects of the more serious threats to critical safety functions.
While the status tree system advises the operator of any threats to the critical safety functions and suggests a procedure to be followed, the operator must still locate the recommended procedure in the paper procedures and then follow it manually step by step. The status tree system also does not keep the operator apprised of other plant conditions which the paper procedures require to be monitored, but which do not directly affect the critical safety functions.
Accordingly, it is an overall object of this invention to provide a method and apparatus for aiding the operator of a complex process facility in executing plant procedures.
It is a more specific object of the invention to aid the operator of a complex process facility by providing a computer based system and a method of operation which incorporate montored plant data and interactive plant operator responses to recommended actions for step by step progression through a selected procedure.
It is a further object of the invention to provide such a system and method of operation which simultaneously, while providing step by step interactive progression through a selected procedure, provide parallel information to the operator concerning other plant conditions which may require attention.
It is an additional object of the invention to provide a system and method of operation which generate a permanent record of appropriate system and process conditions at the completion of each step of each procedure or at periodic intervals of time, so that the actual progress of the operator through the procedures can be reconstructed at a later time.